1. Field of the Invention
In repairing or replacing modern rubber tires of automobiles, wheelbarrows, boat trailers and the like, the rubber bead at the inner diameter of the tire must be forced axially over a ridge on the metal rim in order to place both tire beads in the dropped center of the rim. After this is done prying tools can be inserted which will spring the beads locally over the flanges of the rim. The initial act--forcing the tire bead toward the axial center of the rim--is called "breaking the bead". This invention provides a means both inexpensive and portable for the first step in dismounting the tire--breaking the bead.
2. Description of Prior Art
Because the bead portion of a rubber tire is stiff, strong and inflexible particularly in the radial direction, the former practice of using heavy hammers, even in conjunction with prying tools, does not suffice to break the bead on modern rims. The force applied needs to be large enough, sustained enough, and local enough to get a portion of the tire bead over the customary ridge on the rim. Thus there is no way, any longer, that hand tools and brute strength can break a bead.
Tire-repair machines such as are used in tire repair shops and tire replacement shops are ordinarily hydraulically or pneumatically powered. Thus they require air compressors or hydraulic pumps and the motors to power them. Also, ordinarily the machine is heavy and permanently mounted, since capabilities other than breaking the bead are usually incorporated in the design. However, hand tools can be used for all the auxiliary functions of these machines, hence--except for convenience and speed--the commercial tire-repair machine is the only prior art for breaking tire beads, and it typically requires an air compressor and drive motor as well.